Process for fabricating polarized organic photonics devices

ABSTRACT

A polarized organic photonics device, including an LED or photovoltaic device, is comprised of a first conductive layer or electrode coated with a friction transferred alignment material, a photoactive material, and a second electrically conductive layer or electrode. The alignment material provides for the orientation of the subsequently deposited photoactive material such that the photoactive material interacts with or emits light preferentially along a selected polarization axis. Additional layers and sublayers optimize and tune the optical and electronic responses of the device.

FIELD OF THE INVENTION

[0001] Photonics is the science and technology of generating andharnessing light and other forms of radiant energy whose quantum unit isthe photon. The science includes light emission, transmission,deflection, amplification and detection by optical components andinstruments, lasers and other light sources, fiber optics,electro-optical instrumentation, related hardware and electronics, andsophisticated systems. The range of technical applications of photonicsto devices extends from energy generation to detection to communicationsand information processing and storage. In addition to its otherproperties, the polarized nature of light can be exploited to expand orimprove the efficiency, utility, and specificity of photonics devices.

TECHNOLOGY REVIEW

[0002] Organic based photonics devices have been under development formore than 12 years and offer many potential advantages and opportunitiesfor improved devices. For example, organic electroluminescence (theemission of light in response to an electrical current) has been used indisplay technology. In such a device, organic materials which posses theability to emit light when electric current is passed through them areorganized as thin layers between two electrodes. The emitters used inlight emitting diodes (LEDs) such as these can be either small organicmolecules or conjugated polymers.

[0003] Organic materials are useful for other photonics devices as well.For example, the need to develop efficient low-cost photovoltaic devices(devices that convert light into electrical energy) has stimulatedresearch efforts using organic materials as or as part of thephotoactive media. Photovoltaic devices based on organic materials suchas organic molecules and conjugated polymers are emerging as analternative technology to more conventional approaches based oninorganic semiconductors. Compared to inorganic semiconductorcounterparts, organic materials offer the advantages of highphotosensitivity, high optical absorption coefficients, andcompatibility with vacuum deposition, thereby possessing the potentialfor large area, thin-film devices that can be produced at a modest cost.Furthermore, organic materials can be deposited on flexible or shapedsubstrates, which may eventually lead to the development of lightweightand conformal devices.

[0004] One fascinating feature of organic materials is their potentialfor controlling macroscopic material properties by manipulating theorder or orientation of the molecules. For example, alignment of anorganic material along a given axis can yield preferential absorptionand emission along that axis. LEDs using aligned photoactive materialswhich can emit polarized light will be particularly useful as backlightsfor conventional liquid crystal displays (LCDs), since in these systems50% of the emission of an unpolarized light sources is typically lostdue to polarization based filtering. In addition, control of thealignment of emissive molecules in LEDs is quite important for futureadvancement in emission devices, such as LEDs integrated withmicrocavities and waveguide structures.

[0005] Research efforts directed at achieving polarizedelectroluminescence by aligning the organic emitters have been reported.However, all of these approaches are non-general, have difficultycontrolling film thickness and uniformity, and are time consuming. Forexample, there is the liquid crystal approach. Devices based on thismethod are inherently limited to being made from materials that areliquid crystals. Epitaxial growth on rubbed substrates is anotherapproach that has been attempted. This method is only applicable to usewith small organic molecules which can be vapor deposited. An elongationapproach has also been tried; but this method is complicated and filmthickness and uniformity are difficult to control. The Langmuir-Blodgettmethod has also been used to develop polarized electroluminescentdevices; but it has limited applicability and is specifically limited tomaterials that are amphiphilic and are capable of formingLangmuir-Blodgett films.

[0006] Electronic organic devices developed using apoly(tetrafluoroethylene) (PTFE) oriented film as a template to providealignment and orientation of subsequently deposited films have beenreported. See Katsuya Wakita, U.S. Pat. No. 5,546,889. Such devices are,however, fundamentally limited to electronic devices such as fieldeffect transistors because, among other reasons, the electrodes used inthese devices are necessarily co-planar and hence are inapplicable tophotonics devices. Moreover, because the electrodes are co-planar, it isnot feasible to prepare multiple stacked layers between the electrodes.Furthermore, Wakita is limited to purely electronic devices and does notenable photonics devices since it provides for neither photoactivematerials nor for any electrodes to be transparent. Absent these andother features, such a device is not suitable for photonicsapplications. The electronic device developed by Wakita is alsounsuitable for photonics applications because it fails to overcome theproblem of charge conduction through the PTFE alignment layer, which iselectrically insulating. That is, it fails to answer the question of howto use a polymer, such as PTFE, for alignment without completelyinsulating charge conduction in an organic electronic device.

[0007] To date, polarization sensitive organic photovoltaic devices havenot been reported.

[0008] For the foregoing reasons, there is a need for polarized organicphotonics devices. Moreover, there is a need for a processing methodthat is simple and fast, applicable to a variety of organic andpolymeric materials, yields high optical quality films, and easilyachieves thickness of a few tens of nanometers.

SUMMARY OF THE INVENTION

[0009] The present invention is directed to polarized organic photonicsdevices, and process for production thereof, that satisfies the need forpolarized organic photonics devices, and processes for productionthereof, as well as other needs.

[0010] The process for fabricating a polarized organic photonics devicebeings with preparing a alignment layer on top of a first conductinglayer or conducting substrate. The first conducting layer or conductingsubstrate serves as a first electrode in the photonics device. Thealignment layer, typically a thin layer of an insulating, electrontransporting or hole transporting material, is deposited by a frictiontransfer method. This layer provides for the alignment of subsequentlydeposited organic and polymeric layers, necessary for polarized emissionand absorption. Following the alignment layer, a conducting polymer maybe deposited onto the alignment layer. This step may be carried out atelevated temperatures to enhance the uniformity of the deposited layer.Next, a photoactive material is deposited. As used herein, a photoactivematerial is a material that interacts with or emits light. This step mayalso be carried out at elevated temperature, to enhance uniformity andto further increase the alignment of the photoactive material to thepreferred direction defined by the alignment layer. Finally, a secondconductive layer is added to yield a polarized organic photonics device.The second conductive layer serves as a second electrode in thephotonics device.

[0011] Specific advantages of the present invention include, amongothers, the following:

[0012] (i) A simple method of generalized applicability for creatingpolarized organic photonics devices.

[0013] (ii) Organic photonics devices with enhanced efficiency due tothe polarized response of aligned photoactive material.

[0014] (iii) Organic photonics devices with enhanced selectivity due tothe polarized response of the aligned photoactive material.

[0015] (iv) The ability to simultaneously align organic or polymericspecies using a layer of a alignment material that may be electricallyinsulating without eliminating charge conduction through the alignmentlayer.

BRIEF DESCRIPTION OF THE FIGURES

[0016]FIG. 1 shows the cross section of an embodiment of the inventionas a four layer polarized organic light emitting diode.

[0017]FIG. 2 shows the cross section of an embodiment of the inventionas a five layer polarized organic light emitting diode, which includes aconducting polymer layered between the alignment material and thephotoactive material.

[0018]FIG. 3 shows the cross section of an embodiment of the inventionas a polarized organic photovoltaic device.

[0019]FIG. 4 shows the chemical structures of some of the species usedin the polarized organic photonics devices.

[0020]FIG. 5 shows the polarized micrographs of a photoactive polymercast on a substrate with a friction transferred PTFE alignment layer.

[0021]FIG. 6 shows the parallel and perpendicular absorption spectra ofa PPV12 film cast on a substrate with a friction transferred PTFEalignment layer.

[0022]FIG. 7 shows the parallel and perpendicular photoluminescencespectra of a PPV12 film cast on a substrate with a friction transferredPTFE alignment layer.

[0023]FIG. 8 shows the parallel and perpendicular electroluminescencespectra of one embodiment of the invention as an LED using 1G6-OMe asthe photoactive material.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The polarized organic devices described herein and the methodsfor their fabrication are based on forming a sequence of stacked layersof selected materials in a selected order. The thickness of each of thelayers depends on the material and the intended device application. Forthe limited purpose of describing the layer ordering and the structureof the photonics devices and their formation, except where specifiedotherwise, layers as used herein are understood to be quasi2-dimensional objects such that they essentially have only two surfaces.Thus, when, for example, layer B is formed or deposited on an outersurface of layer A, only one outer surface of layer B remains exposed.Then, if layer C is subsequently formed on an outer surface of layer Bit is understood that the configuration described is a sequence of threelayers stacked in the unique order A-B-C. Additionally, it is understoodthat any layer, unless specified otherwise, may consist of a sequence ofsublayers.

[0025] The process for fabricating a polarized organic photonics devicecomprises the steps of preparing a sequence of stacked layers by firstforming an alignment layer on top of a first conducting layer orconducting substrate. The first conducting layer or substrate serves asa first electrode in the photonics device. The alignment layer providesan alignment template and direction to orient photoactive materials,which are subsequently deposited onto the previous layer or layers. Asecond conducting layer (which serves as a second electrode in thephotonics device), thereby forming a polarized organic photonics device.

[0026] The alignment layer provides for the alignment of subsequentlydeposited organic and polymeric layers, a prerequisite for a polarizeddevice. The alignment layer, typically a thin layer of an insulating,electron transporting, or hole transporting material, is deposited by afriction transfer method. In one preferred embodiment, the alignmentmaterial is poly(tetrafluoroethylene) (PTFE). The alignment layer may beother materials as well. Another suitable material is poly(phenylene)(PPP). U. Ueda et al. 331 Thin Solid Films 216 (1998), incorporatedherein by reference, teaches that ultra-high molecular weightpolyethylene (UHMWPE) may be used as an alignment layer. F. Motamedi 32J. Polymer Sci: B 453 (1994), incorporated herein by reference, teachthat polyethylene, the thermotropic liquid-crystalline Vectra®, andfluorinated ethylene-propylene copolymers are also suitable for theformation of oriented layers by friction transfer.

[0027] The friction transfer method used to prepared the alignment layeron the electrically conductive substrate is achieved by pressing a solidstructure (pellet, bar, ingot, rod, stick or the like) of the alignmentmaterial against the substrate and drawing the solid alignment materialacross the structure in a selected direction under a pressure sufficientto transfer a thin layer of the alignment material onto the substrate.The selected direction of the friction transfer, typically, though notnecessarily, a single linear axis, provides an orientation direction forthe alignment of subsequent layers. The friction transfer method isdescribed more fully in U.S. Pat. No. 5,180,460, which is incorporatedherein by reference. The substrate may either be heated or unheated tooptimize the transfer and control the thickness of the transferredalignment film. Oriented friction transfer alignment structuresfacilitate nucleation and formation of highly oriented structuresdeposited thereon. U.S. Pat. No. 5,772,755, incorporated herein byreference, teaches that a thin film of PTFE also may be prepared for useas an alignment layer by spreading a powder or dispersion across thesubstrate. These deposition methods of U.S. Pat. No. 5,772,755 isincluded under the scope and meaning of the friction transfer method.

[0028] The thickness of the alignment layer should be sufficient toimpart alignment on subsequent layers. It should also be thin enoughsuch that it is not completely insulating. Preferably, the averagethickness of the alignment layer should be less than 10 nm. Morepreferably, the average thickness should be less that 1 nm.

[0029] In one preferred embodiment, following the alignment layer, anelectrically conducting polymer may be deposited onto the alignmentlayer. This step may be carried out at elevated temperatures to enhancethe uniformity of the deposited layer. Alternately, the conductingpolymer may be deposited at room temperature, or below, to yieldpreferential deposition in regions with less PTFE, or other alignmentmaterial. In this latter method, the addition of the conducting polymeryields a more uniform base for subsequently deposited layers. This stepof depositing an electrically conducting polymer may be carried outusing a gaseous-phase, aerosol, casting or melt method. It is preferablethat the conducting polymer is poly(3,4-ethylenedioxythiophene) (PEDOT),polyaniline, polypyrrole, or conducting polythiophene.

[0030] Next, either directly onto the alignment layer, or, in thepreferred embodiment containing the alignment material and conductingpolymer bi-layer structure, onto the bi-layer structure, a photoactivematerial is deposited. The photoactive material itself may a multi-layerstructure. In one preferred embodiment, the photoactive layer consistsof a photoactive material layered between a hole transporting materialon one side and or an electron transporting material on the second side.The photoactive material may also be a blend of or sequence of stackedlayers of one or more photoactive materials.

[0031] The photoactive material may be an organic or polymeric material.If the photoactive material is an organic molecule, it may be1,2-bis(di-4-tolylaminophenyl)cyclohexane (TAPC) or3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). If the photoactivematerial is a polymer, it may be a rigid, linear conjugated polymer.Preferably, the photoactive material may be a polymer such as poly{[2,5-bis(n-dodecan-1-yloxy)-1,4-phenylene] vinylene-1,4-phenylenevinylene} (PPV12), poly{{2-methoxy-5-[3′,4′,5′-tris(n-dodecan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylene vinylene} (1G12-OMe), poly{{2-methoxy-5-[3′,4′,5′-tris(n-hexan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylenevinylene} (1G6-OMe), or poly{{2,5-bis[3′,4′,5′-tris(n-dodecan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylenevinylene} (1G12-S).

[0032] The photoactive material may also be blended or layered withother materials to enhance or modify the optical and or electronicresponses of the photonics device. For embodiments of the presentinvention that operate by the absorption of light, such as photovoltaicdevices, fullerenes are a suitable additive to the photoactive materialto enhance device response. In the present invention, fullerene means acarbon allotrope, which is also called carbon cluster. The fullereneshitherto known are those having such molecular formulas as C₆₀, C₇₀,C₇₆, C₇₈, C₈₂, C₈₄, C₉₀, C₉₆, etc. In the present invention, a mixturecan be used which comprises two or more of these fullerenes. Of these,preferred for use in the present invention are C₆₀ and C₇₀, andparticularly preferred is C₆₀. Substituted fullerenes, fullerenederivatives, polymers comprising fullerenes or substituted fullerenesmay also be blended or layered with the photoactive material.

[0033] The deposition of the photoactive material may also be carriedout at elevated temperature, to enhance uniformity and to furtherincrease the alignment of the photoactive material to the alignmentlayer or bi-layer. This step may be carried out by contacting thephotoactive material with the alignment layer (or bi-layer structure)with the photoactive material in a gaseous phase or as an aerosol, froma solution by a casting method, or as a solid by melt processing. In onepreferred embodiment, the substrate is heated to a temperature above theboiling point of the solution used to cast the photoactive material ontothe alignment layer (or bi-layer structure). This method is valuable inthat it induces alignment of the photoactive material beginning from thesubstrate.

[0034] It is preferable that the first and or the second electricallyconductive layers, both of which serve as electrodes for the device, betransparent or semi-transparent to light. Possible conductive layersinclude indium tin oxide (ITO) or a conducting polymer, both of whichmay be optically transparent. The electrically conducting layer may alsobe a metal film, such as gold, aluminum, silver, or copper. If thislayer is to be transparent, or substantially transparent, then themetallic layer may be relatively thin and still conduct electricity butalso transmit light. One of the conducting layers may also bereflective, or semi-reflective, or selectively reflective, to, forexample, direct unabsorbed light back into the active material, in thecase of a photovoltaic device, or to direct emitted light out of thedevice into a preferred direction, in the case of a LED.

[0035] The first electrically conductive layer is preferably formed on asubstrate. This substrate may be optically transparent orsemi-transparent to allow light to enter and or leave the device. Thesubstrate may be any shape. It may preferably be substantially planer,concave, or convex. The shape of the substrate, as well as its othermaterial and optical properties, may be chosen and or designed tocontrol the transmission and or reflection of light into and or out ofthe device by, for example, focussing, collimating, or diverging light.Additionally, the conducting layers may be conformal with a surface ofany arbitrary shape.

[0036] For certain applications, such as photovoltaic devices, it ispreferred that the two electrodes have different work functions.

[0037] The polarized organic photonics device may be designed to performa number of functions. Among these functions, the device, for example,may be used as a polarized organic light emitting diode. FIG. 1 depictsone embodiment of the current invention in the form of a four layer LED.Substrate 10 serves as a support for a transparent electricallyconductive electrode 11 made from ITO, which is coated with a frictiontransferred PTFE layer 12, and onto which a layer of photoactivematerial 13 has been formed, an aluminum electrode 14 is the final layerin the stacked sequence and the device can be operated as an LED byapplying an electrical signal across the circuit 15 connecting the twoelectrodes.

[0038]FIG. 2 depicts one of the preferred embodiments of the inventionin the form of a five layer LED. Substrate 20 serves as a support for atransparent electrically conductive electrode 21 made from ITO, which iscoated with a friction transferred PTFE layer 22, and onto which aconducting polymer layer 26 has been formed, and onto which a layer ofphotoactive material 23 has been formed, an aluminum electrode 24 is thefinal layer in the stacked sequence and the device can be operated as anLED by applying an electrical signal across the circuit 25 connectingthe two electrodes.

[0039] The polarized organic photonics device may also be designed to bea polarized photovoltaic device. FIG. 3 depicts one of the preferredembodiments of the invention where the device is a photovoltaic device.Light enters the device through an optically transparent substrate 30,which serves as a support for an optically transparent electricallyconductive electrode 31, onto which a friction transferred PTFE layer 32has been formed, and onto which a layer of the photoactive material 33is formed, and with the final layer in the stacked sequence is a secondelectrically conductive electrode 34. A photo-induced electrical signalmay be measured or an electrical load may be driven in the circuit 35,which connects the two electrodes.

[0040]FIG. 4 depicts the chemical structures of some of the chemicalspecies that may be used in the polarized organic photonics devices ofthis invention.

[0041] The examples are provided for illustrative purposes only, and arenot intended to limit the scope of the present invention, which isdefined in the appended claims.

EXAMPLE 1

[0042] This example demonstrates the process of preparing polarizedorganic photoactive layers by casting on a friction transferred PTFEtreated substrate. First, PTFE was rubbed on glass substrates.Photoactive polymer layers, approximately 100 nm thick, were thendeposited on the PTFE treated substrates by casting from solution.Polarized micrographs of PPV12 and 1G6-OMe, the structures of which areshown in FIG. 4, prepared according to this method are shown in FIG. 5.The PTFE component is sufficiently thin and colorless and does notcontribute significantly to light intensity through crossed polarizers.When the film is rotated and the PTFE friction direction is orientedparallel to the polarizer, almost complete extinction of the transmittedlight is observed. This indicates that most polymers are orientedparallel to the PTFE friction transfer direction.

[0043]FIGS. 6 and 7 show the parallel and perpendicular absorption andphotoluminescence spectra from thin films cast from PPV12/chloroformsolution on PTFE rubbed glass substrates. Intensities of absorption andemission along the friction transfer direction (parallel) are muchhigher than those obtained from the perpendicular direction. The ratiosbetween the parallel and perpendicular are 4.1 to 1 and 6.7 to 1 forabsorption and emission, respectively. Energy transfer in the film afterphotoexcitation probably causes the difference between the two ratios.

[0044] Each material deposited on the PTFE treated substrates exhibitspolarization-dependent UV-vis absorption and fluorescence. The intensitywas in every case maximum when the electric field vector was parallel tothe PTFE friction transfer direction, indicating that the conjugatedbackbones were preferentially aligned along the PTFE chain axis. Theeffect of the side chains of the photoactive material on the alignmentwas studied by polarized absorption and fluorescence spectroscopies.In-plane dichroic ratios (intensity parallel vs. perpendicular) for fourpolymers measured after being prepared according the method described inthis example are listed in Table I. The structures of these polymers aredepicted in FIG. 4. All polarized photoactive polymer films wereprepared according to the method of this example. The thickness of eachpolymer film was approximately 100 nm. From Table I, it is apparent thatfewer and smaller side chains leads to greater anisotropy, which isindicative of a greater degree of photoactive material alignment andorientation the film gets. The highest anisotropy was obtained in thethin film of PPV12. TABLE I Dichroic absorption and photo luminescenceratios for polymers cast on PTFE treated substrates Dichroic RatioPolymer Absorption Photoluminescence PPV12 4.1 6.7 1G6-OMe 3 4.2 1G12-S2.7 3.3 2G6-S 1.6 1.7

EXAMPLE 2

[0045] This example demonstrates how the process of preparing polarizedphotoactive layers is used to yield a polarized organic light-emittingdevice. First, an indium-tin-oxide (ITO) coated substrate, heated to200° C., was rubbed as per the friction transfer method with a solidpiece of PTFE. Second, a thin film of photoactive material 1G6-OMe wasprepared by casting solutions of the photoactive material in chloroformor tetrahydrofuran onto the preheated (100° C.) substrate. The synthesisof this photoactive material, and others used herein, has been reportedelsewhere. The film thickness of the active material was approximately100 nm, as measured by a profilometer with 1 nm resolution and confirmedwith optical absorption measurements. The multi-layer structure wasdried in a vacuum oven at 60° C. for 24 hours. Finally, 100-130 nm thickaluminum electrodes were vacuum evaporated (at 10-6 Torr) onto theactive layer. The structure of this device is shown schematically inFIG. 1.

[0046]FIG. 8 shows the electroluminescence (EL) spectra of this device.As described in the fabrication steps above, the sequence of layers is:ITO/PTFE/1G6-OMe/Al. The EL measurement was made in the ambientenvironment and at room temperature. The measurement was taken insequence such that the EL measurement from parallel direction was takenafter the measurement from the perpendicular direction. The lineshape ofthe EL spectrum is identical to both the photoluminescence (PL) spectrumand a non-aligned, unpolarized LED with layers in the sequence ofITO/1G6-OMe/Al, indicating that the PL and EL are from the same species.An anisotropy (ie. ratio intensity parallel to perpendicular) of 2.6 inEL was achieved with the aligned, polarized photonics device of thisexample.

EXAMPLE 3

[0047] This example demonstrates the relative enhancement of thepreferred embodiment that includes a layer of conducting polymerinterposed between the alignment layer and the photoactive layer. Thisexample further demonstrates that, as unique from all prior art,friction transfer alignment layers can induce alignment in organic andpolymeric layers even when an additional organic layer is interposedbetween them. Under conditions essentially identical to those of Example2, it was found that devices with a PEDOT layer interposed between thePTFE and the photoactive material have superior performance in terms ofstability, quantum efficiency, and brightness. A device of thisstructure is shown schematically in FIG. 2. Devices with the structureITO/PTFE/PEDOT/1G6-OMe/Al have comparable quantum efficiency (2.0×10⁻³)to unoriented LED devices without PTFE treatment such asITO/PEDOT/1G6-OMe/Al (quantum efficiency 2.2×10⁻³). Devices with a PTFEalignment layer but without the addition of a conducting polymer layer,such as ITO/PTFE/1G6-OMe/Al, have lower efficiency (1.0×10⁻³). Theseresults, along with those of Example 2, suggest (1) current can passthough PTFE layers, probably by tunneling; and (2) PEDOT helps currentinjection and improves EL performance.

EXAMPLE 4

[0048] This example illustrates one of the preferred embodiments of theinvention wherein the polarized organic photonics device is a polarizedorganic photovoltaic device. In this embodiment, the active materialshere can be a single component, blends or multilayers, and can bealigned with the help of PTFE layer. In FIG. 3 the light absorbingactive materials sandwiched between two conducting electrodes, at leastone of which should be transparent or semitransparent (for light topass). Although not intended to be limited by theory, when the light isshined on the device (through the transparent electrode), the absorbedlight energy (absorbed by active materials) first results in the highlyefficient generation of excitons (electron-hole pair) in the bulk filmof the photoactive material. Due to the concentration gradient, theseexcitons diffuse to a contact, impurity, interface (between component ifsingle layer blend) or organic/organic interface (if multilayer), atwhich point they dissociate into free carriers. Charge separation isfollowed by carriers transport to the contacts, which can then becollected in the external circuit (because of the potential differencebetween the two electrodes). In the device configuration of FIG. 3, theactive material is aligned along a certain direction defined by thefriction transfer deposition of the alignment layer. The response tolight polarized in this direction is stronger than other directions andabsorption of more light leads to greater electrical signals. Table Icontains the anisotropic absorption ratio for a number of activematerials deposited on a friction transferred alignment layer.Therefore, this device is more sensitive than others since allchromophores can take part in absorbing light, in contrast to a devicewith randomly orientated chromophores where only light parallel todipole moment of chromophores gets absorbed. Furthermore, the devicedescribed in this example can detect the polarization of the light.

[0049] The materials for the first electrodes in this device may be ITO,Au, Ni, and other semitransparent or transparent conducting materials.Materials suitable for the second electrode include any conductingmaterials, and need not necessarily be transparent. For applicationssuch as photovoltaic devices, it is preferred that the two electrodeshave different work functions. Materials for photoactive layer may be,for a single layer, a PPV12-C₆₀ blend. For a bilayer device, a suitablesequence of layers and materials is, for example: ITO/PTFE/p-typematerials (e.g. PPV12)/n-type materials (e.g. PTCDA)/Al. In thisconfiguration, because the work function of ITO is greater than that ofAl electrons will go to the Al electrode and holes will go to the ITOelectrode. Alternately, the configuration could be:ITO/PTFE/PPV12-n-type materials blend (e.g. C₆₀)/p-type materials (e.g.TAPC)/Au. In this configuration, since the work function of Au isgreater than that of ITO electrons will go to the ITO electrode andholes will go to Au electrode.

[0050] It is understood that various other modifications will beapparent to and can be readily made by those skilled in the art withoutdeparting from the scope and spirit of this invention. Accordingly, itis not intended that the scope of the claims appended hereto be limitedto the description set forth above but rather that the claims beconstrued as encompassing all of the features of patentable noveltywhich reside in the present invention, including all features whichwould be treated as equivalents thereof by those skilled in the art towhich the invention pertains.

What is claimed is:
 1. A method of manufacturing a polarized organicphotonics device, the method comprising forming a sequence of stackedlayers by the steps of: (a) preparing a first layer having an outersurface, and comprising a first electrically conductive material; (b)forming a second layer having an outer surface, and comprising anoriented alignment material applied by friction transfer on said outersurface of the first layer; (c) forming a third layer having an outersurface, and comprising an oriented layer of a photoactive material bycontacting said photoactive material with said outer surface of thesecond layer; and (d) forming a fourth layer comprising a secondelectrically conducting material by depositing said second electricallyconducting material on said outer surface of the photoactive material.2. The method of manufacture of a polarized organic photonics deviceaccording to claim 1, wherein at least one of the electricallyconducting materials is transparent or semi-transparent to light.
 3. Themethod of manufacture of a polarized organic photonics device accordingto claim 2, wherein at least one of the electrically conductingmaterials is indium tin oxide, a thin metallic film, or an opticallytransparent conducting polymer.
 4. The method of manufacture of apolarized organic photonics device according to claim 1, wherein thefirst and second electrically conducting materials have different workfunctions.
 5. The method of manufacture of a polarized organic photonicsdevice according to claim 1, wherein the first electrically conductivematerial is prepared on a substrate.
 6. The method of manufacture of apolarized organic photonics device according to claim 5, wherein thesubstrate is transparent or semi-transparent to light.
 7. The method ofmanufacture of a polarized organic photonics device according to claim5, wherein the substrate is substantially planer.
 8. The method ofmanufacture of a polarized organic photonics device according to claim5, wherein the substrate is concave or convex.
 9. The method ofmanufacture of a polarized organic photonics device according to claim1, wherein the alignment material has an average thickness of less thanabout ten nanometers.
 10. The method of manufacture of a polarizedorganic photonics device according to claim 9, wherein the alignmentmaterial has an average thickness of less than about one nanometer. 11.The method of manufacture of a polarized organic photonics deviceaccording to claim 1, wherein the alignment material is selected fromthe group consisting of poly(tetrafluoroethylene), poly(phenylene),polyethylene, poly(dimethylsilane), poly(diethylsilane),poly(di-n-hexylsilane), poly(di-n-butylsilane), andpoly(methylphenylsilane).
 12. The method of manufacture of a polarizedorganic photonics device according to claim 1, wherein the photoactivematerial comprises a blend or sequence of stacked layers of one or morephotoactive materials.
 13. The method of manufacture of a polarizedorganic photonics device according to claim 1, wherein the photoactivematerial comprises a photoactive material layered in a stacked sequencebetween a hole transporting material on one side and or an electrontransporting material on a second side.
 12. The method of manufacture ofa polarized organic photonics device according to claim 1, wherein thephotoactive material is an organic or polymeric material.
 15. The methodof manufacture of a polarized organic photonics device according toclaim 14, wherein the photoactive polymeric material is a rigid, linearconjugated polymer.
 16. The method of manufacture of a polarized organicphotonics device according to claim 14, wherein the photoactive materialis a member of the group consisting ofpoly{[2,5-bis(n-dodecan-1-yloxy)-1,4-phenylene] vinylene-1,4-phenylenevinylene}, poly{{2-methoxy-5-[3′,4′,5′-tris(n-dodecan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylene vinylene}, poly{{2-methoxy-5-[3′,4′,5′-tris(n-hexan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylenevinylene}, poly{{2,5-bis[3′,4′,5′-tris(n-dodecan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylenevinylene}, 1,2-bis(di-4-tolylaminophenyl)cyclohexane and3,4,9,10-perylenetetracarboxylic dianhydride.
 17. The method ofmanufacture of a polarized organic photonics device according to claim1, wherein the photoactive material is blended or layered in a stackedsequence with fullerenes, substituted fullerenes, fullerene derivatives,polymers comprising fullerenes or substituted fullerenes.
 18. The methodof manufacture of a polarized organic photonics device according toclaim 1, wherein the photoactive material is contacted with the outersurface of the alignment material in a gaseous phase or as an aerosol,from a solution by a casting method, or as a solid by melt processing.19. The method of manufacture of a polarized organic photonics deviceaccording to claim 1, wherein the alignment material is heated when thephotoactive material is contacted with the outer surface of thealignment layer.
 20. The method of manufacture of a polarized organicphotonics device according to claim 19, wherein the alignment materialis heated to a temperature above the boiling point of a solvent usedwhen the photoactive material is in solution when contacted with thealignment layer.
 21. The method of manufacture of a polarized organicphotonics device according to claim 1, wherein the photoactive materialfurther comprises a layer of an electrically conducting polymer formedon the outer surface of the alignment layer by contacting a conductingpolymer with the alignment material prior to forming a layer of thephotoactive material.
 22. The method of manufacture of a polarizedorganic photonics device according to claim 21, wherein the formation ofthe conducting polymer on the outer surface of the alignment material iscarried out using a gaseous-phase, aerosol, casting, or melt method. 23.The method of manufacture of a polarized organic photonics deviceaccording to claim 21, wherein the conducting polymer ispoly(3,4-ethylenedioxythiophene), polyaniline, polypyrrole, orconducting polythiophene.
 24. A method of manufacturing a polarizedorganic photonics device, the method comprising forming a sequence ofstacked layers by the steps of: (a) preparing a first layer having anouter surface, and comprising a first electrically conductive material;(b) forming a second layer having an outer surface, and comprising anoriented alignment material applied by friction transfer on said outersurface of the first layer; (c) forming a third layer having an outersurface, and comprising a conducting polymer on said outer surface ofthe second layer; (d) forming a fourth layer having an outer surface,and comprising an oriented layer of a photoactive material by contactingsaid photoactive material with said outer surface of the third layer;and (e) forming a fifth layer comprising a second electricallyconducting material on an outer surface of the fourth layer.
 25. Apolarized light emitting diode produced according to the process ofclaim
 1. 26. A polarized light emitting diode produced according to theprocess of claim
 24. 27. A polarized photovolatic device producedaccording to the process of claim
 1. 28. A polarized photovolatic deviceproduced according to the process of claim
 24. 29. A polarized organicphotonics device, which comprises a sequence of stacked layersincluding: (a) a first layer having an outer surface, and comprising afirst electrically conductive material; (b) a second layer having anouter surface, and comprising an oriented alignment material applied byfriction transfer on said outer surface of the first layer; (c) a thirdlayer having an outer surface, and comprising an oriented layer of aphotoactive material on said outer surface of the second layer; and (d)a fourth layer comprising a second electrically conducting material onsaid outer surface of and in electrical contact with the photoactivematerial.
 30. A polarized organic photonics device as claimed in claim29, wherein at least one of the electrically conducting materials istransparent or semi-transparent to light.
 31. A polarized organicphotonics device as claimed in claim 30, wherein at least one of theelectrically conducting materials is indium tin oxide, a thin metallicfilm, or an optically transparent conducting polymer.
 32. A polarizedorganic photonics device as claimed in claim 29, wherein the first andsecond electrically conducting materials have different work functions.33. A polarized organic photonics device as claimed in claim 29, whereinthe first electrically conductive material is prepared on a substrate.34. A polarized organic photonics device as claimed in claim 33, whereinthe substrate is transparent or semi-transparent to light.
 35. Apolarized organic photonics device as claimed in claim 33, wherein thesubstrate is substantially planer.
 36. A polarized organic photonicsdevice as claimed in claim 33, wherein the substrate is concave orconvex.
 37. A polarized organic photonics device as claimed in claim 29,wherein the alignment material has an average thickness of less thanabout ten nanometers.
 38. A polarized organic photonics device asclaimed in claim 37, wherein the alignment material has an averagethickness of less than about one nanometer.
 39. A polarized organicphotonics device as claimed in claim 29, wherein the alignment materialis selected from the group consisting of poly(tetrafluoroethylene),poly(phenylene), polyethylene, poly(dimethylsilane),poly(diethylsilane), poly(di-n-hexylsilane), poly(di-n-butylsilane), andpoly(methylphenylsilane).
 40. A polarized organic photonics device asclaimed in claim 29, wherein the photoactive material comprises a blendor sequence of stacked layers of one or more photoactive materials. 41.A polarized organic photonics device as claimed in claim 29, wherein thephotoactive material comprises a photoactive material layered in astacked sequence between a hole transporting material on one side and oran electron transporting material on a second side.
 42. A polarizedorganic photonics device as claimed in claim 29, wherein the photoactivematerial is an organic or polymeric material.
 43. A polarized organicphotonics device as claimed in claim 42, wherein the photoactivepolymeric material is a rigid, linear conjugated polymer.
 44. Apolarized organic photonics device as claimed in claim 42, wherein thephotoactive material is a member of the group consisting ofpoly{[2,5-bis(n-dodecan-1-yloxy)-1,4-phenylene] vinylene-1,4-phenylenevinylene}, poly{{2-methoxy-5-[3′,4′,5′-tris(n-dodecan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylene vinylene}, poly{{2-methoxy-5-[3′,4′,5′-tris(n-hexan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylenevinylene}, poly{{2,5-bis[3′,4′,5′-tris(n-dodecan-1-yloxy)benzyloxy]-1,4-phenylene}vinylene-1,4-phenylenevinylene}, 1,2-bis(di-4-tolylaminophenyl)cyclohexane and3,4,9,10-perylenetetracarboxylic dianhydride.
 45. A polarized organicphotonics device as claimed in claim 29, wherein the photoactivematerial is blended or layered in a stacked sequence with fullerenes,substituted fullerenes, fullerene derivatives, polymers comprisingfullerenes or substituted fullerenes.
 46. A polarized organic photonicsdevice as claimed in claim 29, wherein the photoactive material iscontacted with the outer surface of the alignment material in a gaseousphase or as an aerosol, from a solution by a casting method, or as asolid by melt processing.
 47. A polarized organic photonics device asclaimed in claim 29, wherein the alignment material is heated when thephotoactive material is contacted with the outer surface of thealignment layer.
 48. A polarized organic photonics device as claimed inclaim 47, wherein the alignment material is heated to a temperatureabove the boiling point of a solvent used when the photoactive materialis in solution when contacted with the alignment layer.
 49. A polarizedorganic photonics device as claimed in claim 29, wherein the photoactivematerial further comprises a layer of an electrically conducting polymerformed on the outer surface of the alignment layer by contacting aconducting polymer with the alignment material prior to forming a layerof the photoactive material.
 50. A polarized organic photonics device asclaimed in claim 49, wherein the formation of the conducting polymer onthe outer surface of the alignment material is carried out using agaseous-phase, aerosol, casting, or melt method.
 51. A polarized organicphotonics device as claimed in claim 49, wherein the conducting polymeris poly(3,4-ethylenedioxythiophene), polyaniline, polypyrrole, orconducting polythiophene.
 52. A polarized organic photonics device,which comprises a sequence of stacked layers including: (a) a firstlayer having an outer surface, and comprising a first electricallyconductive material; (b) a second layer having an outer surface, andcomprising an oriented alignment material applied by friction transferon said outer surface of the first layer; (c) a third layer having anouter surface, and comprising a conducting polymer on said outer surfaceof the second layer; (d) a fourth layer having an outer surface, andcomprising an oriented layer of a photoactive material on said outersurface of the third layer; and (e) a fifth layer comprising of a secondelectrically conducting material on an outer surface of and inelectrical contact with the fourth layer.
 53. In a liquid crystaldisplay having a means of illumination, the improvement comprising theuse of the apparatus of claim 29 as a polarized light emitting diode forback-lighting.
 54. In a liquid crystal display having a means ofillumination, the improvement comprising the use of the apparatus ofclaim 52 as a polarized light emitting diode for back-lighting.
 55. In aphotodetector having a means of detecting light, the improvementcomprising the use of the apparatus of claim 29 as a polarizedphotovoltaic device for detection of polarized light.
 56. In aphotodetector having a means of detecting light, the improvementcomprising the use of the apparatus of claim 52 as a polarized devicefor detection of polarized light.